Rekenrek

Ways to use it in class

• One push. Ask for 7 in a single push, not seven taps. Children who can do it are using the five: all the red and two white.
• Making ten. Show 6 on one row and ask how many more fill it. The count line says how many more make 10.
• Doubles and near doubles. Show 5 and 5, then 5 and 6. Ask how the second picture helps with 5 + 6.
• Quick looks. Press Flash: the rack shows for two seconds and covers. Ask how many and how they saw it, then reveal.
• Tens to 100. With ten rows, 47 is four full rows and seven more. Count on by tens, then by ones.

Printing a rekenrek

Press Print for the rack as it is: slide beads to show a number for a worksheet, or Clear it for a rack students color in.

Questions teachers ask

What is a rekenrek?

A counting frame designed at the Freudenthal Institute in the Netherlands; the Dutch name means "arithmetic rack". It has two rows of ten beads, and each row is five red beads and five white. The color change at five lets a child see 7 as five and two more, and 10 as a full row, without counting one by one. In English it is also called a number rack.

How is a rekenrek different from an abacus?

On an abacus a bead's row gives it a value, ones, tens or hundreds. On a rekenrek every bead is worth one, and the fives and tens are shown by color and by the row. It is a tool for number sense and early adding, not for place value.

How do you move the beads?

In one push, the way children use a real rack. Tap a bead on the right and it slides to the left along with every bead to its left. Tap a bead on the left and it goes back along with every bead to its right. To show 8, tap the eighth bead once.

What are doubles and near doubles on a rekenrek?

Show the same number on both rows, such as 6 and 6, and the 12 can be seen as two fives and two ones. For 6 + 7, show 6 on top and 7 below: one more than a double. Set Fill to Shared and press Slide to split any number across the rows this way.

Which rack should I use?

One row of ten for kindergarten counting and making 5 and 10, two rows for numbers to 20, doubles and adding within 20, and ten rows, a hundred beads, for counting by tens and adding to 100 in grades 1 and 2.